Combination locks



March 31, 1959 R. L. EICHBERG COMBINATION LOCKS 2 Sheefs-Sheet 1 Filed Oct. 7. 1953 INVENTOR Roberz L. fz'chbe g W z/ag,

RELEASE DEV/CE AGENT March 31, 1959 R. L. EICHBERG 2,879,657

COMBINATION LOCKS Filed 001;. '7. 195a 2 Sheets-Sheet 2 IIIIIII IHIIIIIIII III INVENTOR AGENT Un w t tes Patent COMBINATION LOCKS I U Robert L. Eichherg Dunn Loring, Va. Application October 7, 1953, Serial No. 384,803 I v 12 Claims. to]. 70-267) (carted under Title 35, U. s. code 1952 sec 266) The invention described herein may be manufactured and used by or for the Government of the United States for governmental purposes without the payment to me oi any royalty thereon in accordance with the provisions of 35 United States Code (1952) section 266. it

My invention relates to a new and useful improvement in locks of the combination, or .permutation, type., The well known mechanical combination lock commonly used on ordinary steel safes is an example of the type of lock to which-my invention is applicable. However, myinvention is also applicable to permutation'locks of the electrical type and indeed has additional advantages when appliedto electrical locks. t

My invention relates particularly to two aspects of existingycombination locks. First, existing combination locks impose no inherent limiton the time available for completingthe setting of the combination. Second, existing combination locksof the electrical type require either (a) an external-or battery source of current or (b) a generator that is hand-operated by a separate and additional control.

A principal object of my invention is to provide an additional safety or security feature for combination locks of either the electrical or themechanical type, reducing the possibilitythat an unauthorized person, not knowing the combination, will be able to open the look.

A second principal object of my invention is to provide, formcombination locks of the electrical type, a source of electrical energy powered by operation of the same main controldial that is used to operate the combination.

Anotherobject of my invention is to provide a simple and economical method of modifying the design of combination-locks,,of either the electrical or mechanical type, in such mannerthat the security value of the lock will besubstantially increased.

Another object of my invention is to provide a combinationmechanism that will not permit actuation of a latching device, on a given attempt, unless the combinationis correctly completed within a short predetermined time.

Another object of my invention is to provide a combination mechanism that, before it is actuated to produce release of an associated latching mechanism by setting of the combination dial to the correct combination, must be preconditioned by spinning the main control dial with which the combination is set, the arrangement being such that-saidpreconditioning loses its effectiveness after a limited'predetermined time, so that on a given attempt the-mechanism will not be effective unless the combination'is-correctly'completed within such limited predetermined time after such preconditioning.

A further object of my invention is to provide an electn'cal-permutation mechanism having fewer controls than existing electrical permutation locks, such mechanism accordingly being more attractive to the consumer and more marketable than existing electrical permutation locks.

In applying my invention to electrical permutation locks, I prefer to use a capacitor shuntedby a bleeder resistor to store the energy needed to actuate the mechanisrn release mechanism. I prefer to charge the capaci tor by rectifying the output of an alternating-current generator that is operated by spinning the control shaft. Unless the combination is correctly completed withina predetermined time after the charging of the capacitor, the energy remaining in the capacitor will no longer be sufiicient to permit actuation of the latch release mechamsm. 1

Other uses and advantages of the invention will become apparent upon reference to the specification and drawings.

Figure 1 shows an embodiment of my invention in a combination mechanism of th e electrical type.

Figure Z shows an embodiment of my invention in a combination mechanism of the mechanical type.

The combination mechanism illustrated in Fig. 1, is of conventional construction and includes a control knob f1 fastened to a numbered dial 2 and to a shaft 3. Shaft 3 passes through journal hearings in the center of a series of combinationdisks 4, 5, and 6. The combination disks are made of electrically insulating material, but each disk has on its front and back face a number of radial electrically conducting strips 7, 8, 9, etc. These are preferably printedcircuits, for economy of both cost and space. On each disk one opposed pair of these strips, and only one pair, are electrically connected to each other by means of electrically conducting pins 10, 11 and 12, which pass through the insulating body of the disk. As will be readily understood by those skilled in the art, the combination can be changed by changing the combination of these pins. Electrically conducting brushes 13, 14,15, 16, 17, and 18 make contact with each face of each disk.

As is evident, the electrical circuit between brush'13 and brush 18 will he completed when, and only when, allof the three disks are so positioned that the electrically connected pair of conducting strips on each disk makes contact with the associated brushes.

This positioning of the combination disks is accomplished, when knob 1 is turned to the proper series of dial numbers, through the action of mechanical pins 19 20, 21 22, 23, and 24. Pin 19 is mounted directly on the back of the dial, or is mechanically constrained to rotate therewith. Pins 21 and-23 are mounted on the back facesof disks 4 and 5, respectively. Pins2tl, 22, and 24 are mounted on the front faces of disks 4, 5, and 6, respectively. The pins are so located that pin 19 strikes one side or the other of pin 20 to drive disk 4 in either direction, and pins 21 and 23 -similarly drive disks 5 and 6 by striking against pins 22 and 24. Alternative methods of keying one disk to the next are also possible.

novel and do not warrant more-detailed description. It

-, will be readily recognized and understood by those skilled in the art that theportions thus far described represent the principal electrical and mechanical'features of an electrical permutation lock in which the circuit between brush 13 and brush 18 is closed when the disks have been properly positioned by turning the control knob to the necessary combination of dial numbers. Whenthe circuit is thus completed, if a suitable source of electrical potential is applied at points E-E, electrical energy will be effective to produce a control effect.

'2' Still referring to Figure 1, my improvement centers about an alternating-current generator 26 driven by control knob 1 and shaft 3; a cold-cathode, solenium or other rectifier 27; a capacitor 28; a resistor 29; and a voltage-limiting device 30 such as a neon tube. To

.charge capacitor 28 with sutficient energy to cause actuationof the release device when the combination is correctly completed, it is necessary that control knob 1 .be

duced by.- g enerator 26,-rectified byrectifier 27, andstored re a ner 2w 31.125?

in capacitor 28. Resistor 29 is so selected in relation to capacitor 28 that capacitor 2 8 will discharge within a predetermined time to the point where it will no longer have sufiicient energy to 'actuaterelease device 25. In other words, when release device 25 is sufficiently energizcd by capacitor 28 it will exert a control effect; but when the energy in capacitor 28 has fallen below a certain critical level such control effect will be inhibited. If an attempt is made to store an unduly great amount of energy in capacitor 28, to provide more time to operate the combination, the voltage-limiting device 30 discharges this excess energy.

The rotor of generator 26 may be fastened permanently to shaft 3, as shown, or may be geared thereto. The amount of energy produced when the dial is slowly rotated a few times, as in setting the combination, is very small compared to the energy produced when the dial is spun rapidly a much larger number of times. The effect of the rotation that the generator receives while the combination is being set therefore has a negligible effect on the charge of capacitor 28.

Although I prefer to use an alternating-current generator in combination with a rectifier, as described, to charge the capacitor or other energy storage device, a direct-current generator may be used alternatively, in combination with a centrifugal switch or other means to prevent discharge of the capacitor back through the generator. However, the alternating-current generator in combination with the rectifier is simple and economical, and the rectifier, in addition to providing D.-C. for charging the capacitor, prevents discharge of the capacitor through the generator. The resistor 29 provides a leakage path for completing the discharge of capacitor 28.

It will be seen that the above-described embodiment of my invention is an improvement over existing electrical combination locks in two principal respects. First,

my invention has the advantage of making it impossible for anyone to actuate the permutation mechanism to produce a control efiect, on a given attempt, unless he is able to complete the combination within a predetermined short time30 seconds, for example. Failing on one attempt, the operator must start all over again by spinning the control dial to recharge the energy storage means. The design can be such that this recharging takes at least several seconds of spinning, and the spinning necessarily entails the destruction of any part of the combination that may have been already correctly set. Manifestly, my improvement serves the useful purpose of greatly reducing the possibility that a person not knowing the combination will succeed in opening a combination lock within any given finite time. Whatever the security value of a given lock in the absence of my improvement, the addition of my improvement to the design will further increase the net security value.

Second, my invention has the advantage of eliminat- 'ing the need of an auxiliary knob or other control, required in previous electrical permutation locks, for operation of the self-contained generator. In other words, my invention makes it possible to construct an electrical permutation lock with a self-contained generator, yet having only the single-knob control that is characteristic of the hitherto-more-widely-used mechanical permutation locks. My invention thus increases substantially the security, convenience, attractiveness, and marketability of electrical permutation locks in relation to mechanical permutation locks. Electrical permutation locks in general have the advantage that, unlike mechanical locks, they can easily be made insusceptible of being opened by unauthorized persons using sound or feel detectors.

On the basis of the foregoing description of a specific embodiment of my invention, it will be understood that my invention may be considered to comprise (1) a first means for the storage of energy, energy for storage in said meansbeing provided by, and only by, spinning the main control dial that controls the opening of the lock;

(2) a second means for making the lock ineffectual, even if the person attempting to open the safe has correctly operated the combination, unless the amount of energy remaining in storage in the first means exceeds a certain value; and (3) a third means for discharging energy stored in the first means, so that after a predetermined lapse of time the first means will no longer "contain suflicient energy to permit the lock to be opened even though the dial combination has been correctly operated. However, my invention will be defined more precisely and fully in the appended claims.

Furthermore, it will be seen that when my invention is embodied in electrical permutation locks, the energy stored in said first means can preferably be in electrical form and can serve as the electrical energy that must be supplied to the release means of any electrical permutation lock. Therefore, as embodied in electrical permutation locks, my invention provides a new and useful method whereby the electrical energy required for the T lock release mechanism can be generated by manual operation of the same main control dial that is used to set the combination.

From the above description, it will be readily apparent that a number of different embodiments of my invention are possible, both in combination locks of the electrical type and in those of the mechanical type. I will now describe briefly a way I now contemplate of applying my invention to combination locks of the mechanical type.

Referring to Figure 2, it is well known to those skilled in the art that, in general, combination locks of the mechanical type use an arrangement of control dial, shaft, and disks mechanically similar to the arrangement of the electrical lock described above and shown in Fig ure 1. In the typical mechanical-type lock, however, each disk has a notch 30, 31, 32 at a certain position on its edge. The typical mechanical lock also has an additional disk 50, of slightly greater diameter than disks 30, 31, 32, that is mounted fixedly on shaft 36 and that has a notch 51 opposite the zero position of the dial. This disk 50 serves to prevent control effect producing bar 34 from entering notches 30, 31, 32 unless bar 34 is already in notch 51. When notches 51, 30, 31 and 32 have all been properly aligned by operation of control dial 33, bar 34 falls into these notches, and this action produces a control efiect by operating a release device 25 that permits the bolt to be operated manually as described in connection with Fig. 1. I v In applying my invention to such a mechanical lock,

I prefer to use a spring motor 35 of the type used in timepieces as my energy storage device. This motor is connected to the main control shaft 36 of the lock. The

motor can be wound-charged with energy-only by I rapidly turning the control dial a relatively large number of times in a predetermined direction. The clockwork mechanism contains a flutter escapement or a governor 37, connected in such a way that the motor immediately begins to run down. To prevent overwinding of the clock mechanism, torque-limiting clutch 52 is inserted in the winding mechanism. The output shaft 38 of the motor is connected through gearing 39 and a shaft 40 to a rotatable cam 41. The'arrangement and I the gear ratios are such that when the motor is in thc unwound condition cam 41 prevents release bar 34 from falling into notches 30, 31, 32 even though the combination may have been correctly set. When the motor is wound up, however, cam 41 is rotated out of the way of bar 34 so that cam 41 offers no impediment to the fall-i ing of release bar 34 into notches 30, 31, 32.

It is desirable that the ratio of gears 39 should be 'so selected, in relation to motor 35, that shaft 40 rotates through one-half revolution when the initially unwound motor is converted to the fully wound condition. In

other words, winding themotor rotates cam 41 to a position directly opposite to the position indicated in Figure 2, and as the motor unwinds cam 41 gradually rotates until it obstructs the end of bar 34.

From what has been said, it will be seen that the mechanical lock shown in Figure 2 cannot be opened unless the operator correctly completes the combination within a limited predetermined time after spinning the dial to store energy in spring motor 35.

The construction of an embodiment of my invention in a lock of the mechanical type as described will naturally involve various minor mechanical problems, but various solutions of these problems will readily occur to mechanically skilled persons.

It will be apparent that the embodiments shown are only exemplary and that various modifications can be made in construction and arrangement within the scope of my invention as defined in the appended claims.

I claim as my invention:

1. In a permutation mechanism of the type having a plurality of combination discs, an operating dial for setting said discs to a predetermined setting and means articulated with said discs for producing a control efiect in response to such setting, the combination of conditionable means normally disabling said control eflFect means and means for enforcing production of said control eifect within a predetermined time interval commencing with initial actuation of said operating dial comprising means responsive to manipulation of said operating dial for immediately selectively activating said disabling means to a condition rendering said control efiect means operable by said discs for said predetermined time period.

2. The invention of claim 1 in which said means for activating said disabling means comprises an energy storage means, means responsive to manipulation of said dial for applying energy to said storage means, means for controlling the rate of discharge of the energy stored in said storage means and means responsive to the level of energy stored in said storage means for deactivating said disabling means to a condition normally disabling said control effect means when the energy remaining stored in said storage means has fallen :below a predetermined level.

3. The invention according to claim 2 in which the means for the storage of energy comprises a capacitor.

4. The invention according to claim 3 in which the means for applying energy to said storage means comprises an electrical generator.

5. The invention according to claim 3 in which the means for applying energy to said storage means comprises an alternating current generator in combination with a rectifier.

6. The invention according to claim 3 in which the means for controlling the rate of discharge of the energy is an electrical load shunted across the said means for the storage of energy.

7. The invention according to claim 2 in which there is additionally provided a means for limiting the maximum amount of energy storable in the said means for the storage of energy.

8. The invention according to claim 7 in which said limiting means comprises a gaseous discharge device.

9. The invention according to claim 2 in which the means for the storage of energy comprises a spring motor.

10. The invention according to claim 9, in which the means for applying energy is a shaft transmitting rotary motion from said operating dial to said spring motor.

11. The invention according to claim 9 in which said means for controlling the rate of discharge of energy is a governor connected to the output mechanism of said spring motor. 7

12. The invention according to claim 10 in which there is additionally provided a torque-limiting clutch connected between said shaft and spring motor for limiting the maximum amount of energy storable in the first energy storage means.

References Cited in the file of this patent UNITED STATES PATENTS 1,118,024 Lawrence Nov. 24, 1914 2,029,272 Miller Jan. 28, 1936 2,322,560 Beck June 22, 1943 

